Heater



`Nov. 14, 1944.

H. J. DE N. MCCOLLUM HEATER Filed Sept. 2, 1942 2 Sheets-Sheet 1 Nov. 14, 1944.

H. J. DE N. MCCQLLUM 2,362,571

HEATER Patented Nov. 14, 1944 UNITED STATES PATENT OFFICE 2,362,571 HEATER Henry J. De N. McCollum, Chicago, Ill.

AApplication September 2, 1942, Serial No. 457,001

8 Claims.

My invention pertains to heaters and is more particularly concerned with the provision of a heater of the internal combustion type.

An object oi my inventiton is to provide a new and improved heater of the internal combustion type having means for pre-heating the combustible mixture.

Another object of my invention is to provide a new and improved heater of the internal combustion type having a new and improved combustion chamber arrangement.

Another object of my invention is to provide a new and improved heater of the internal combustion type which is extremely compact and eilicient. v

Another object of my invention is to provide a v Fig. 2 is a longitudinal section on an enlarged-,

scale or the heater shown in Fig. 1; and

Fig. 3'1is atransverse section taken on the line 3-3 of Fig. 2. i

In Fig. 1, Il have illustrated my invention as being embodiedin a heater III enclosed in a casing I2 for directing the iiow oi' Ventilating air over the heater in such relation that the temperature of'this Ventilating air is raised by heat created in the heater II. The casing I2 has a Ventilating air inlet I4 which may be supplied with `air by a ram, blower, or any other suitable means. The

casing I2 is also-"provided with a Ventilating air l outletV I8 which may open directly into an airplane cabin or any other space to be heated, or may be connected to'asystem of ducts for distributing the heated Ventilating air in any desired manner. l

, The heater I comprises a hollow casting I8 of aluminum or other suitable materiah The casting I8 has an open end which is closed by 'a plate secured to the casting I8 by bolts 22 or in any other suitable or appropriate manner. The plate 20 is preferably cast of aluminum or other metal having relatively high heat conductivity. The

casting I8 has integral, exterior ns 24 which extend lengthwise of the casting I8 and have radially directed in-turned ends 2G. The plate 20 is also provided with integral radially arranged ns 28. The iins 24 and 28 transmit heat to the'ventilating air directed thereover by the casing I2 and are so proportioned and arranged as to prevent over-heating of the casting I8 and plate 20 and minimize the creation of local hot spots therein.

The casting I8 is provided with integral internal iins which extend lengthwise of the casting I8 and have radially directed inlet ends 32. A muffler 34 is located in the casting. I and comprises a sheet metal shell 36 containing a quantity of stainless steel wool 38, or'glass wool, or other suitable sound deadening or heat resistant material. The shell 36 is provided with openings 40 forming acousti-couplings .between the` passages ior the products of combustion and the interior of the muilier 34.

The muiiier shell 36 is constructed and arranged to provide a combustion chamber 42 located interiorily thereof. A burner tube 44 is located in the combustlon".chamber 42 and is supplied with a combustible mixture through a pipe` 46. The

any suitable source.

burner tube 44 is provided with openings 48 through which the combustible mixture passes into the combustion chamber and these openings are preferably so arranged as to give the combus tible mixture a whirling motion as it enters this chamber. l

The combustible mixture entering the combustion chamber 42 is ignited by an electrical igniter 43 which is supplied with electric current from This igniter is vof the hot wire type and a perforated plate 45juis provided to protect the hot wire 41 from the direct flow oi the` combustible mixture. It will be understood that the igniter 43 is preferably provided with the usual thermostatic switch for breaking the circuit of this igniter whenever the heater attains normal operating temperature and thereafter combustion is maintained` by the re-igniter 50, which may be of any usual or suitable type.

The walls oi the combustion chamber 42 are illustrated as being provided with openings 52, .which form acousti-couplings between this chamber and the interior of the muiiier 34. These acousti-couplings assist in the absorption of noises created in the combustion chamber and cooperate with the acousti-couplings 48 in minimizing the operating noise created by the heater.

The hot products of combustion ilow out of the right-hand end of the combustion chamber 42 and enter the spaces between the inlet ends 32 of the internal ns 30. These gases irst flow radially outward and then to the left, as viewed in Fig. 2, between the longitudinal portions of the ns 30. These ns absorb heat from the gases and transit this heat to the exterior fins 24, which in turn give up this heat to the Ventilating air. The cooled gases of combustion then pass into outlet space 54 and are discharged through a Venturi-like restriction 56` provided in a fitting 58 threadedly attached to the plate 20. The iitting 58 is provided with a swivel coupling 60 for attaching this fitting to any suitable exhaust conduit 62.

In the operation of my invention, the combustion chamber 42 is supplied with a combustible mixture through pipe 46 which is connected to an engine supercharger or a carburetor under superatmospheric pressure, or with any other suitable source. Instead. of depending upon a source of combustible mixture under pressure for supplying this mixture to the combustion chamber 42, the exhaust pipe 62 may lead to a' suitable source of suction which will serve to draw the combustible mixture into the combustion chamber 42. In some installations the ilow of combustible mixture into the combustion chamber and the flow of combustion gases therefrom may be induced jointly by means for supplying combustible mixture under pressure to the combustion chamber and means for sucking the gases of combustion therefrom. The combustible mixture is ignited by the igniter 43, which is connected either to the electrical system of the aircraft or is provided with its own battery or other source of electricity. The combustion occurring in the combustion chamber 42 creates heat therein and this heat is communicated to the walls of the combustion chamber. The hot gases of combustion ilow out ofthe combustion chamber into the spaces between the inlet ends 32 of the interior ns 30. These gases then pass to the left, as Viewed in Fig. 2, between the longitudinal portions of the ns 30.

Most of the heat is absorbed from these gases by the fins 30 and is transmitted to the fins 24. Which in turn give up this heat to the Ventilating air directed thereover by the casing i2. It is to be noted that this Ventilating air is projected against the end wall of the casting I8 and that this is the most eliicient arrangement, since this end Wall is heated to the highest temperature by the combustion of the fuel. The inlet end of this casing may be connected with a ram or blower, or other suitable source of air under pressure, or alternatively the outlet end I6 may communicate with a suction blower or other suction producing device.

Any heat remaining in the gases of combustion when they reach the outlet space 54 is absorbed by plate and transmitted to the Ventilating Vair by fins 28. The cooled gases of combustion are then discharged to atmosphere through restriction 56 and exhaust pipe 62. The muffler 34 absorbs audible vibrations present in the combustion chamber 42 or entrained in the combustion gases ilowing between the fins and contributes materially to the silence of operation of my invention. 'I'hls muler is exposed to the heat created in the combustion chamber 42 and to the hot gases discharged therefrom and is maintained at high temperature.

An important feature of my invention lies in the provision for preheating the combustible mixture supplied to the combustion chamber 42. It

will be noted that the inlet pipe 46 for this combustible mixture passes through the plate 20 in intimate contact with the walls of a tubular extension 64 to which pipe 46 is attached by a tubular nut 66 having an in-turned flange 68 engaging an annular enlargement "l0, forming an integral part of, or rigid with, the pipe 46. The pipe 46 and the combustible mixture flowing therethrough absorb heat from plate 20, mufller 34 and the gases located in exhaust space 54 and this preheating of the combustible mixture increases the eciency of the combustion in the combustion chamber 42 and the efficiency of the heater as a whole.

In my novel heater the combustion chamber 42 is located in a recess formed in the muiller 34 and the Walls of this combustion chamber are remote from the Ventilating air and are maintained at high temperature. This feature also contributed to the eiciency of combustion in this combustion chamber and the efciency of the heater as a whole.

The embodiment of my invention which I have illustrated and described is formed of a few relatively simple parts which may be economically manufactured by mass production methods with conventional equipment and by conventional processes. These parts may be readily assembled and the completely assembled heater is compact, efcient and light in w'eight. The design of the individual parts is such that they are inherently strong and they may be as rugged as required for any particular type of service.

While I have illustrated and described only a single embodiment of my invention, my invention is not limited to the details illustrated and described. My invention may assume numerous forms and isto be construed as including all modifications and variations falling within the scope of the appended claims.

I claim:

l. In a heater of the class described, the combination of a. muliler having a recess formed in one end thereof, a pipe extending through said muiiler and supplying a combustible mixture to said recess, heat exchange means enclosing said muffler and providing a passage for burned gases around the exterior of said muiller, and means for directing Ventilating air over said heat exchange means.

2. In a heater of the class described, the combination of a cylindrical Imuiller having a recess providing a combustion chamber in one end thereof, a conduit extending axially of said muiller and providing a combustible mixture to said combustion chamber, a casing surrounding said muffler and having a Wall spaced therefrom to provide a passage for burned gases ilowing from said combustion chamber, means for directing Ventilating air over said casing, and a gas outlet for said casing, said outlet lbeing located at the end thereof which is remote from said combustion chamber.

3. In a heater of the class described, the combination of lmeans including a muiiler providing a combustion chamber, said muiiler including means for supplying a combustible mixture to said chamber, means cooperating with said muiiler to provide a passage for burned gases leaving said combustion chamber, said passage causing said burned gases to ilow in a direction opposite to said combustible mixture and to preheat the latter, and means to transfer heat from said combustion chamber and burned gases to ventilating air.

4. In a heater of the class described, the combination of a hollow, aluminum casting having a closed end and a'n open end, said casting having internal and external integral ns, a plate closing the open end of said casting, said plate having heat radiating tins, a mulller located in said hollow casting and having a recess providing a combustion chamber, said mulder, casting and'plate providing passages about said mui'lier for burned gases from said combustion chamber and connecting said combustion chamber with an outlet provided by said plate, and apipe extending through said plate and the muiller and supplying combustible mixture to said chamber.

5. Ina heater of the class described. the combination of a hollow member having a closed l end and an open end, a combustion chamber therein adjacent said closed end, means providing a passage between that part of the combustion chamber adjacent said closed end and the open end of said member, and means for supplying a preheated combustible mixture to said Combustion chamber, said means including a pipe extending through said open end to said combustion chamber.

6. In a heater of the class described, the combination of a hollow member having a closed end and an open end and comprising a wall located between and integral with internal and external ns, a muier located in said member and spaced from the wall thereof to provide gas passages lengthwise of said internal fins, said muler having a combustion chamber formed in one end thereof and communicating with said passage, a plate attached to the open end o! said member and in spaced relation tosaid mulller, a pipe extending through said plate and muiller for supplying a combustible mixture to said combustion chamber, an igniter mounted in the closed end of said member tor igniting said mixture, a casing enclosing said member and directing ventilating air over the exterior thereof, and an outlet for burned gases provided by said plate.

7. In an internal combustion heater of the class described. the combination of a mumer, a heat exchanger enclosing said mulller and cooperating therewith to provide a combustion chamber and a passage for burned gases discharged from said chamber, said muiller having a passage therethrough communicating with said combustion chamber, means for supplying a combustible mixture to said last-named passage, and means for directing air over said heat exchanger.

8. In an .internal combustion heater of the class described, the combination of a muiner having a sheet metal shell containing sound absorbing material, a heat exchanger cooperating with said mui'lier to provide a combustion chamber and passages for burned gases discharged from said combustion chamber, said shell having a passage therethrough communicating with said combus- V tion chamber, means for supplying combustible mixture to said last-named passage for now therethrough in a direction opposite to the flow oi burned gases in said passages, said shell having small openings connecting the interior thereof with said passages, and means for directing air over said heat exchanger.

HENRY J. DI N. MCCOLLUM. 

